Computing system



March 27, 1934. H. s. JOHNSTONE 1,952,868

COMPUTING SYSTEM Filed June 18, 1929 3 Sheets-Sheet l I //ZZ Ff W M Iwy March 27, 1934.

H. G. JOHNSTONE COMPUTING SYSTEM Filed June 18, 1929 3 Sheets-Sheet 2 March 27, 1934. H. G. JOHNSTONE 1,952,863

COMPUTING SYSTEM Filed June 18 1929 5 Sheets-Sheet 3 [/7 3 W4 W4 4T Patented Mar. 27, 1934 PATENT OFFHE UNITED STATES Application June 18, 1929, Serial No. 32 1,7051

1-9 Claims.

This invention relates to computing systems and more particularly to an electrically operated mathematical multiplication system.

w The primary object of the invention is to provide an eiiicient, accurate, and flexible system for rapidly performing mathematical computations and for automatically increasing the value of a digit by one when the fractional part exceeds a predetermined number.

In accordance with the above object, the in vention contemplates an improvement on a multiplicationr system such as that disclosed and claimed in the copending application of H. Ci. Johnstone and C. W. Robbins, Serial No. 302,462,

filed August 28, 1928, in which the multiplicand and multiplier are set up on keys to close certain electrical circuits through a multiplying apparatus which sends electrical impulses, representing sub-products, through denominational distributing brushes to an accumulating, totalizing,

indicating or registering device. The accumulating device of the present invention is provided with a plurality of switching devices, such as keys or transfer jacks adapted to be engaged by a plug to open and close certain electrical circuits whereby any denominational register of the accumulator can be caused to indicate five while all of the other denominational registers will in.- dicate zero upon the actuation of a switch to clear out the multiplication system. Hence, by inserting the plug in the transfer jack representing the denominational column to be discarded when reading the result and operating the clear out switch, that particular denominational register may .be caused to indicate five, so that if the digit in the denominational column of the result of a computation is five or greater, it will be added to the five initially registered to effect 0 a carry of one to the digit in the next higher denominational column. Thus; for example, assume the result of the computation is $11,494.58'7. The last digit '7 thereof which represents a fractional part of a cent is to be discarded, but since it is more than one-half, the accepted commercial result under these conditions is $11,494.59. In this instance, the operator will use the unit transfer jack to obtain this result.

Other features and objects of the invention will be apparent from the following description when taken in conjunction with the accompanying drawings, in which I Figs. 1 and 2 are circuit diagrams which, when viewed collectively with Fig. 2 to the right of Fig. 1, disclose an electrical multiplying and indicating system representing one embodiment oi? the invention;

Fig. 3 is a fragmentary elevational view of the multiplying and indicating mechanism;

Fig. 4 is a vertical sectional view taken on line 4-4 of Fig. 3;

Fig. 5 is a fragmentary plan view showing a portion of the accumulating, indicating, or registering device;

Figs. 6 and Z are sectional views taken on lines c -e and '5--7, respectively of Fig. 3 showing one of the disk units on the multiplying compute/tor;

Fig. 8 is a side view looking toward the right of Fig. 5 showing the structure of the accumulator for obtaining the return of a denominational reg- 79 ister wheel to five instead of zero, and

Fig. 9 is anenlarged fragmentary schematic of three of thesets of nine each of the contact disks representing the multiplication system on the multiplying commutator.

Referring to the drawings in which similar parts are designated by the same numerals in the several views, it is believed that a clear understanding of the invention will be had therefrom when considered in conjunction with the following description. In examining the circuit diagram, Fig. 2 should be arranged immediately to the right of Fig. 1. In Figs. 1 and 2, the multiplicand and multiplier key banks designated ill generally by the numerals 100 and 101, respec- 35 tively, are represented schematically by a coordinate group of lines, the vertical lines or columns from right to left denoting units (U), tens ('I), hundreds (H), ten-hundreds (TH), and ten-thousands (TT), and the nine rows of cross lines designating the digits 1 to 9 consecutively. Each intersection of the lines represents an electrical contact, normally open, which can be closed by any suitable locking key 102 (Fig. 1) such as described and. disclosed in A. D. Hargan Patent No. 1,378,950, issued May 24, 1921.

Any particular problem of multiplication may 'be set up on the key banks -101 by closing the contacts at the points corresponding to the digits 100 in the multiplicand and multiplier. These contact closures complete electrical circuits through a multiplying commutator and send electrical currents to a distributor switch denoted generally as 106 which directs the currents to an accumu- 105 later 107 for properly registering or accumulating the results. The multiplying commutator 105 comprises an electrical multiplication table in which there are nine sets, designated as 103, of nine electrical 110 contact disks insulated from each other and divided into twenty-seven units of three each, designated by the numeral 104, (Figs. 1, 6, 7 and 9), so adapted that each contact represents one of a series of numbers representing the product of each digit times itself and each other digit running from 01 to 81. Each of the nine sets 103 of nine contact disks represents the numbers 1 to 9 consecutively and are connected to individual conductors leading to the corresponding digit in the multiplicand key bank 100. The contact disks are insulated from and secured to a rotatable shaft 108 journaled in bearings 109--109 fastened to a frame 110 (Fig. 3). The shaft 108 is rotated by means of a gear 115 fastened thereto meshing with a spur gear 116 of a speed reducer 117 which is driven by a belt 118 from a motor 119 rigidly secured to the frame 110. Each unit 104 of three contact disks is also provided with an associated feed disk 140 (Fig. 6) for making connections with the digit cross lines in the multiplicand key bank. The contact disks have individual brushes and are so constructed that the position of a contact on onehalf of the circumference represents the unit number of the particular product of two digits and a contact on the other half the tens part.

Figs. 6 and '7 show one of the units 104 of three disks 125, 126 and 127 representing the products of multiplying 2 by 1, 9, and 2, respectively. These disk units 104 are similar in construction to sequence switches commonly used in telephone exchange systems. The three copper disks 125, 126 and 127 are mounted on an insulator 128 and are electrically interconnected due to the fact that the disks 126 and 127 are integral and are connected with the disk 125 by means of copper rivets 129 passing through the insulator and serving to hold the elements together as the unit 104. The insulator 128 is keyed to the commutator shaft 108 and insulates the associated copper disks therefrom. Disk 125 has one radial contact 132 representing the product 02 of 2x1 to be engaged by a brush 133 at a predetermined point in the rotation of the unit 104; the disk 126 has two radial contacts 134 and 135 representing the tens digit 1, and the units digit 8 of the product 18 of 2x9 to be engaged by a brush 136; and disk 127 has a contact 137 representing the product 04 of 2x2 to be engaged by a brush 138. A feed brush Fig. 9, the enlarged fragmentary schematic of the multiplying commutator, shows the arrangements of the multiplication table for three of the sets 103 representing the digits 1, 2 and 3. The multiplication table as illustrated follows the series of 1 1,1 9,1 2,1 3,1 4,1 5,1 6, 1 7, and 1x8; 2 1, 2x9, 2x2, 2x3, 2X4, 2x5, 2x6, 2X7, and 2x8; 3 1, 3x9, 3x2, etc., wherein each of the contacts represents a particular product. The multiplication table follows the usual order except that the digit 9 is placed between the digits l-and 2 to simplify the interconnecting of the circuits. It will be clear that the multiplication tables for the numbers 4 to 9, in-

elusive, are followed in a similar manner throughout the length of the multiplying commutator.

Secured to the multiplying commutator shaft, but electrically insulated therefrom, is a control commutator 145 (Fig. 2) consisting of circular switches K, L, and M for closing and opening various circuits at predetermined intervals throughout the multiplying cycle, the actual purpose of which will be clearly understood as the description progresses.

A dial 146 (Fig. 3) attached to the commutator shaft 108 and rotatable therewith is divided or marked to indicate twenty-eight equal parts so that each division marking indicates a particular rotative position of the shaft 108 and its associated disk-units 104 rigidly mounted thereon relative to a fixed starting point. The positions one to twenty-eight are adopted to describe more clearly the sequence of events as the multiplying commutator 105 passes through one complete revolution, and it is to be noted, as previously mentioned, that the units part of a product of two digits is registered during the first half cycle of one to fourteen, inclusive, and during the second half of the cycle, positions fifteen to twenty-eight, inclusive, the tens part is registered where the product consists of two digits (more than nine).

The distributor switch 106 (Fig. 1) is provideo for transferring the electrical connections from units to tens, tens to hundreds, hundreds to ten hundreds, etc., as the multiplication progresses to complete an electrical circuit to the proper electromagnets in the accumulator or register 107. The distributor switch is similar in design to selector switches used in telephone systems and comprises in general a shaft 147, an electromagnet 148 (Fig. 2) for rotating it one step at a time, six brushes 149 to 154, inclusive, (Fig. 1) insulatively mounted upon the shaft, and arcuate banks 144 of twenty-two stationary contacts adapted for cooperation with said brushes. Five of the brushes 149 to 153, inclusive, designate and are connected by conductors to the units (U), tens (T), hundreds (H), ten-hundreds (TH), and ten-thousands (TT) columns in the multiplicand key bank 100. The sixth brush 154 applies ground progressively to one of the columns indicating units (U), tens (T), hundreds (H), in the multiplier key bank 101 as the multiplication advances to close the circuit therefrom through the multiplying commutator 105, multiplicand key bank 100, distributor switch 106, and the accumulator 107 to battery and ground.

The accumulator 107 can be remotely situated from the multiplicand and multiplier key banks to register the products of the multiplication and comprises in this embodiment of the invention eight rotatable brushes 160 to 167, inclusive, representing units (U) to ten millions (TM) coiumns in the final product, respectively, which brushes are adapted to make wiping engagement with an arcuate bank of contacts 168 having stationary terminals numbered 1234-- 5-6--'789--0. The stopping of a brush on a particular terminal designates the number marked thereon so that it will be readily understood that the accumulator 107 registers digits proportional to the length of time the brushes 160-167 are rotated.

The rotation of the accumulator brushes 160 to 167, inclusive, is accomplished by an electromagnetically operated means which will now be described; referring to Figs. 2, 3, 4, 5, and 8 of the drawings, a shaft 171 suitably journaled on the frame has a gear 172 secured thereto meshing with an idler gear 1'73 which in turn meshes with the gear driving the shaft 108 of the multiplying commutator 105. The rotating shaft 171 has rigidly mounted thereon a plurality of spaced gears 1'74 adapted to drive gears 175 (Figs. 4 and 5) fastened to shafts 176 carrying loosely mounted sleeves 177 to which the brushes 160167 are rigidly secured. Slidably keyed to and rotatable with the shaft 176 is a clutch member 178 having a serrated face 1'79 for engaging a companion serrated face 180 of the sleeve 177 to cause rotation thereof. The slid able and rotating clutch member .178 is provided with a groove 184 into which extends the bifurcated end of an armature 185 of an electromagnet 196 of any suitable. type. A compression spring 187 is associated with the armature 185 to separate the driving clutch member 1'78 from engagement with the brush carrying sleeve 17? the eiectromagnet 186 is de-energized. From the foregoing it will be obvious that the energizing of the electromagnet 186 will move the armature 185 thereof to compress the spring 18'? and lock the serrated faces of the clutch zneniher 178 and the sleeve 177 together to cause the rotation of its associated brush.

An index or register wheel 188 integral with each sleeve has a series of twenty depressions on its periphery, which depressions are adapted to he engaged by a roller 189 mounted on a compression leaf spring 190 to center the brush with relation to the position of the stationary terminals in the arcuate bank 168. Each depression has a number engraved therein starting with l and running consecutively as 2, 3, 4, 5, *8, 7, 8, 9 and 0 so that there are provided two complete sets of in= dicating numbers on each register wheel. These numbers are so positioned .on the periphery of the wheel that the depression immediately above the roller 189 indicates the number designated by its amociated brush. For example in Fig. 4 the brush 167 has stopped on the terminal 9 and the operator by looking at the depression 191 immediately above the rollerreads the number 9 engraved therein. The use of the two complete sets of indicating numbers on each register wheel 188 gives a rapid indication in that a digit is registered for each half revolution of an index wheel.

In order to facilitate an understanding of the working relationship of the details of the computing system and to afford a more effective means of describing many important functions thereoflsuch as the carry function of the accumulator and its method of simultaneously carrying tens to higher denominational orders, an explanation will be given of the steps performed in a specific example such as multiplying 7,229.3 by $1.59.

To accomplish this multiplication the driving motor 119 (Fig. 3) is connected to a suitable source of power (not shown) to cause continuous rotation of the multiplying commutator 105 and of the shaft 176 of the accumulator switch 106 as has been previously described. Keys 102 in the multiplicand and multiplier key 'banks 100 101 (Fig. 1) corresponding to the numbers 7,229.3 and 1.59, respectively, are then depressed, as indicated by the circles, to close electrical circuits at those points. Since the product of 7,229.3 and $1.59 will produce a result TMM HT TT TH HTU $11, 4 9 4 .587 having three decimal places, and it is. desired that the result be indicated in dollars and the nearest even number of cents, it is obvious that the units (U) column of the product is to be discarded. It will be assumed that the accumulator indicates the result of a previous computation and in order to clear out the accumulator and at the same time return the units (U) column register to a five indication so that the units digit i in the result to be indicated, which in this case is greater than five, will be added to the five registered at the start to effect a carry of one to the digit in the tens (T) denominational column, the operator inserts a telephone plug into the units (U) transfer jack 192 (Fig. 2) whereby electrical circuits are established to accomplish the desired object as will be clearly understood as the description progresses. Although the use of a plug-and jack is described, it will be obvious that any suitable type of key can be used in place of the plug and jack.

itith these preliminary adjustments made, the operator momentarily presses a start key 195 which closes a circuit from grounded battery 196, conductor 197, and the winding of a starting relay 198 to ground. Relay 198 upon being energized establishes a locking circuit for itself from ground through its winding and right hand conand armature, conductor 199, and the winding of the electromagnet 148 of the distributor switch, to grounded battery. The current flowing through the distributor magnet 148 at this time is not sufficient to operate it, but it is suflicient to maintain relay 198 energized. The closure of the left hand contact of relay 198 connects brush 4 of the circular switch M of the control commutator 145 to ground, through conductor 201, conductor 250, and the back contact of a clear-cut switch 202. When the control commutator 145, which runs continually as a part of the multiplying commutator 105, reaches position 1, as indicated by the dial 146 (Fig. 3) a circuit is established through brushes M4 and M2, conductor 203, left hand winding of a pick-up relay 204, conductor 213, and the back contact and armature of a release relay 205 to grounded battery. Pick-up relay 204 is thereby energized and establishes a locking circuit for itself through its right hand inner contact and right hand winding.

The operation of the pick-up relay 204 also establishes a circuit from ground through brushes L4 and L2 of the control commutator 145, conductor 209, left hand inner contact of'relay 204, conductor 210, conductor 199 to the winding of distributor switch magnet 148. The circuit just traced is closed for twenty-five degrees of rotation from position 1 of the control commutator and performs two functions: It operates the distributor switch magnet 148 advancing the distributor brushes 149 to 154, inclusive, to stationary terminals 1 in the plurality of banks 144; and causes the short circuiting of the winding of starting relay 198 to thereby open its contacts and render the relay ineffective in the circuit. The pick-up relay 204 also establishes a circuit from brush L3, conductor 211, left hand outer contact of relay 204, conductor 208, conductor 212 to brush 154 of the distributor switch 106; the pick-up relay 204 also establishes another circuit from battery through the back contact of release relay 205, conductor 213, right hand outer contact of relay 204, conductor 214, the winding of a carry relay 215, conductor 245, brushes K3 and K4 to ground. The entire operation up to this point is a preliminary or preparatory function to place in the cycle.

The beginning of the actual multiplying operation occurs at rotative position 4 of the multiplyin'g and control commutators when brush L3 makes contact and applies ground which will hereinafter be designated as the master ground. Ground is thereby established from brushes L4 and L3 through conductor 211, left hand outer contact of pick-up relay 204, conductor 208, conductor 216, and the winding of a relay 217 to grounded battery. The operation of relay 217 closes contacts to complete individual circuits from the units (U), tens (T), hundreds (H), etc., columns in the multiplicand key bank 100 to their respective brushes 149-153 of the distributor switch 106. At the same time the master ground is supplied to the units column in the multiplier key bank 101 through brush 154, terminal 1 of its associated bank 144, and conductor 218. Contact 9 in the units column of the multiplier key bank 101 being closed due to the depression of that particular key, the master ground is continued through conductor 122 to a contact in each of the nine sets 103 of the multiplying commutator 105. This contact in each case as previously described is so cut that it is closed in the first half of the cycle, positions 1 to 14, inclusive, at a point representing the digit in the units (U) column of the product of 9 times the number of the set.

The ground from the contact 9 of the units (U) column in the multiplier key bank 101 is thus continued on through the various multiplying commutator junctions at the contacts representing the various digits of the products to the corresponding digit cross-lines of the multiplicand key bank 100. At this point the circuit from the master ground finds digit cross-lines connected through to the distributor switch 106 according to the specific problem set up on the multiplicand key bank 100. The first closure in the first half cycle is in the 2 set of the sets 103; that is, 9 times 2 which closes at rotative positions 7. An illustration of the specific construction of the unit 104 having disks representing the products of multiplying 2 by 1, 9, and 2 can be had by referring to Fig. '7 of the drawings wherein the disk 126 has a radial conta t 135 representing the units digit 8 of the product 18 of 9 times 2, which contact at rotative position 7 of the multiplying commutator makes a wiping engagement with a brush 136 connected to the conductor 122 (Figs. 1 and 9). As previously explained, the

disk 126 is electrically connected through copper rivets 129 to a feed disk 140. This feed disk contacts continually with a feed brush 139 which is connected to a conductor 224, establishing a circuit to the digit 2 cross-line in the multiplicand 1,229.3 in the problem assumed, the hundred (H) and ten-hundred (TH) columns in the multiplicand key bank 100 are connected to the digit 2 cross-line, connecting the master ground at this time to conductors 225226, the hundreds (H) brush 151 and the ten-hundred (TH) 152 of the istributor 106, which brushes being on terminals 1 of the banks 144 continues the ground through conductors 227 228, conductors 229 230 to the hundreds (H) and ten-hundreds (TH) electromagnets 186 of the accumulator 107, through conductor 231 to battery. These hundred (H) and ten-hundred (TH) electromagnets 186 operate, engaging their clutches 178 (Fig. 5) and starting rotation of the hundred (H) and tenhundred (TH) brushes 162 and 163 (Fig. 2). At the same time hundred (H) and tenhundred (TH) holding relays 236 (Fig. 1) are operated, over the same path and in parallel with the accumulator magnets 186. The holding relays lock up through their own contacts to conductor 216, conductor 208, left outer contact of the pick-up relay 204, conductor 211 to the brushes L3 and L4 in the control commutator, thereby holding the master ground to the hundred (H) and tenhundred (TH) accumulator magnets when the contact 135 of the disk 126 opens its circuit an instant later by rotating out of engagement with the brush 136.

One position later in the cycle, position 8, a brush 142 (Fig. 9) connected to the conductor 122 finds a contact closure, representing the units digit '7 of the product 27 of 9 times 3, through one of the disk units 104 in set 3 of the multiplication sets 103, through conductor 239, contact closure between the digit 3 cross-line and the units (U) column in the muiltplicand key bank. conductor 240, left outer contact of relay 217 to the units brush 149 of the distributor switch 106. Since the brush 149 is resting on terminal 1 of the associated bank 144, the circuit is contined through conductor 241, units (U) electromagnet 186 of the accumulator, and conductor 231 to battery.

The energization of this units (U) magnet 186 operates its associated clutch 178, and consequently causes the rotation of brush 160. At the same time the units (U) holding relay 236 locks up through its own contact to keep the units (U) electromagnet 186 operated after the 9 times 3 contact in the multiplying commutator has been opened. At position 12 the junction of 9 times 7 finds itself connected through to the ten thousands ('IT) magnet and operates and looks it. At position 14the 9 times 9 junction operates and locks the tens (T) magnet in the same manner. One unit of rotation after this, which is position 15, the contact of the L3 brush is opened to break the master ground which has maintained all of the accumulator magnets 186 and relays 236 operated, allowing the clutches 1'78 to release. The TT, TH, H, T and U accumulator brushes 164, 163, 162, 161 and 160 have been carried ahead 3, 3, 8, 1, and '7 spaces representing the units digit of the products of 9 times '7, 2, 2, 9 and 3, respectively.

When the commutators 105 and 145 have rotated to position 15 the K3 brush of the control commutator 145 closes a circuit from ground, through brushes K4 and K3, conductor 245, the winding of the carry relay 215, conductor 214, right outer contact of relay 204, conductor 213, back contact of the release relay 205 to battery, and thus energize the carry relay 215, The operation of the carry relay 215 is for the purpose of searching for a tens carry to be described. Since the units (U) accumulator brush 160 registered five at the start due the prior clearing out of the multiplying machine with the plug previously inserted in the units (U) transfer jack 192, and the brush 160 has been advanced seven spaces representing the units digit of the product of 9 3 to indicate 2, which is the units digit of the sum 12 of 7 plus 5, it will be noted that the brush in passing from terminal 5 to 2 made contact with a terminal 248 (Fig. 2) inserted between the terminals 9 and 0 in the bank 168. The terminal 248 is connected to a relay G1 which is operated over a circuit from grounded battery at the C1 relay, through its winding, conductor 232, terminal 248, associated brush 160, conductor 250, the back contact of the clearmenace out switch 202 to ground. Upon operation, the C1 relay looks from battery through its winding, through its right hand contact, conductor 251, and to ground through brushes K1 and K4 of the control commutator 145 when rotating between positions 20 and 4 or when rotating between positions 6 and 18. These positions, 26 to t and 6 to 18, include the positions in which the multiplying commutator is effective for controlling the rotation of the accumulator brushes. At rotative position 16, the K2 brush supplies ground to each of the left hand armatures C1 to C? relays, through a circuit from brush K2 of the control commutator 145, conductor 252, to the left hand contact of the relays C1 to (37. Since only the units (U) accumulator brush 162 has passed from 9 to (l, the Cl relay alone is on erated and the ground from the K2 brush passes from the left hand armature of the Cl relay through conductor 242, right hand outer contact of the relay 215, conductor 2433, to the winding of the tens (T) accumulator magnet 166 which is operated. At rotative position 17 the brush opens the above circuit, releasing the tens E) clutch 178 after the tens (T) brush 161 has been rotated or advanced one unit to the next higher number thereby increasing the value oi the digit in the tens (T) denominational colunui since the digit in the units (U) column is 5 or greater and the units (U) column is to be discarded or omitted in reading the result. Also, position 15 the L2 brush closes for 25 operating the mag net 146 and advancing the distributor brushes 149 to 154, inclusive, to terminals 2 in the banks lt l/ The system is now ready to proceed. with the registering of the tens digit of the aforcmen tioned multiplication.

At rotative position 16, the L3 brush again closes to the master ground and the distributor brush 154 directs the ground to the units (U) column of the multiplier key bani: 161 because terminals 1 and 2 of the associated bani: led are connected together. The previous operation of the clutches 1'28 is repeated except that the second half of the cycle, positions 15 to 26, inclusive, represents the tens digit of each product; that is, 8 of 9 times 9, 6 of 9 times 7, 2 oi 9 times 3, 1 of 9 times 2 and 1 of 9 times 2. Distributor brushes 149 to 153 have been advanced to torminals 2 so as to connect the units (U) column of the multiplicand key bank 100 and its asso ciated units (U) holding relay 236 to the tens (T) accumulator magnet 186, through conductor 240, distributor brush 149, terminal 2, conductors 246 and 2&7, the winding of the tens (T) ac cumulator magnet to battery. In a similar manner, the tens (T) column of the multiplicand key bank is connected to the hundreds (H) ac cumulator magnet; the hundreds column to the ten hundreds (TH) accumulator magnet, etc. This efiects the rotation of the proper accumulator brushes to register the tens digits of 9 times the multiplicand 72,293 and is completed at rotative position 28 when the L3 brush opens the master ground in the control commutator 145. The multiplication accomplished upto this point is as shown:

brushes 164, 163, and 162, respectively, in the first cycle of the assumed problem afiords an illustration oi the method of carrying tens to higher denominational orders and will be described in detail. As already explained, the TI, TH, T and U accumulator brushes receive 3, 8, 6, 1 and "i, respectively, in the first half of the cycle; and in the second half of the cycle, the HT, TT, Tl-l, H and T brushes receive 6, l, l, 8 and 2, re spectively. Now it will be noted that the H brush 162 has received 2 and S totaling 16, but has stopped on terminal 6 in the arcuate bank 168. However, in passing from terminals 9 to (l, the brush 162 made contact with an added terminal 242 in the bani; 168. This terminal 248 is con nected to relay G2 which is operated over the following circuit; from battery at the ('32 relay, through its winding, conductor 2429, through the added terminal 242, through the associated. brush 162, conductor 25d, the baclr. contact of the clearout switch 222 to groimd. Upon operation, the C2 relay lcclrs from battery through its whirling, through its right contact, conductor 251, and to ground through brushes K1 and lid of the con trol commutator when rotating between posi tions 26 and 4 or when rotating between positions 6 and 12. In the meantime, the ten-hundreds ("i acciunulator brush 163 has received digits 2 nd i, stopping upon terminal 9 or the assc ciated arcuate terminal bani: 163 the ten. thousands (TT) accumulator brush id i has received the digits 3 and l, stopping upon terminal l, As rotative position i arrives, the L3 brush opens the circuit from the master ground, causing the actuated accumulator brushes to stop rotating and releasing the relay 21'? (Fig. l) there by disconnecting the accumulator magnets '66 from the multiplicand lsey bani; 16c and the sociated holding relays 236. At rotative position 1, the K3 brush operates the carry relay 215 over the path previously described, and at position the K2 brush supplies ground to each of the left hand armatures of the C1 to (3'7 relays, through a circuit from brush K2 of the control committator 145, conductor 252, to the left hand contact of the relays C1 to (37. Since only the hundreds (I-l) accumulator brush 162 has passed from to (l, the (32 relay alone is operated, and the ground from the K2 brush passes from the left armature of the C2 relay, conductor 252, right middle contact of relay 215, conductor 254, to the winding of the ten-hundreds (TH) accumulator magnet 186 which is operated. At rotative posi tion l the K2 brush opens the above circuit, re leasing the ten-hundreds (TI-l) clutch 1'78 after the ten-hundreds (TH) brush 163 has been rotated or advanced one unit to the next higher number. This is the carry tens function which transfers one digit to a register of the next higher order when the lower register passes from 9 to (l.

The mode of accomplishing-a plurality of tens carrys simultaneously to the next higher denomination is illustrated by the ten-hundreds (TI-l) accumulator brush 163. It is to be noted at this point that the ten-hundreds (TH) brush 163 has received 8 and l, totaling 9, at the same time that the hundreds (H) brush 162 received 8 and 8, totaling 16, so that it will be seen that the tenhundreds (TH) brush 163 came to rest on terminal 9 before the carry operation of the tens digit 1 from the total 16 on the hundreds (H) brush.

Referring to Fig. 2, contact disks 260 to 267, inclusive, which are part of the accumulator or indicating mechanism, are shown schematically directly under each of the accumulator brushes 160 to 167, inclusive, respectively. These disks are of a construction similar to the aforementioned sequence switches and are secured to the sleeves 177 and rotate with their respective accumulator brushes as illustrated in Fig. 5. Each of the disks comprises an insulator with superimposed pieces of conducting material connecting with brushes, Z, F and C, respectively, except the disks 260, 261 and 267 which have only the brushes Z and F. The disks 260 and 263, inclusive, in addition, each have a 5 brush and when a plug is inserted in any one of the denominational transfer jacks 192 the corresponding associated Z brush is rendered inoperative. The feed brush F is always in contact and the brush designated as C is connected when, and only when, the associated accumulator brush is standing on the 9 terminal in the companion bank 168. This arrangement establishes a circuit whereby the carry current which was connected to the ten-hundreds (TI-I) accumulator magnet 186 is conducted also to the ten-thousands (TT) accumulator magnet and the two accumulator magnets operate simultaneously by virtue of the fact that the ten-hundreds (TI-l) accumulator brush 163 was standing on the 9 terminal when the carry current arrived. Starting at the point where the ten-hundreds (TI-l) accumulator magnet is energized to carry the tens digit 1 of the product 16 from the hundreds (H) accumulator brush 162, the simultaneous carry circuit is traced as follows: The winding of the ten-hundreds (TH) accumulator magnet, conductor 254, brushes F and C of the disk 263, conductor 269, left hand middle contact of carry relay 215, conductor 270, the winding of the tenthousands (TT) accumulator magnet, conductor 231, to battery thereby to operate the ten-thousands (TT) accumulator magnet at the same time that the ten-hundreds (TH) accumulator magnet is operated. If a succession of the accumulator brushes were standing on terminals 9 and a carry current was supplied to the accumulator magnet of the one of lowest order, all of the accumulator brushes of the higher ones would advance and indicate zero simultaneously. This carry function is effect ve only during that part of the cycle reserved for the tens carry; namely, rotative positions 1 to 3, inclusive, and positions 15 to 17, inclusive. This is true because the carry function is controlled by the carry relay 215 which is operated only during that part of the cycle named.

During the period that the carry function was being performed, the L2 brush in rotating from positions 1 to 3 closed a circuit previously described to energize the eleetromagnet 148 and advanced the distributor brushes 149 to 154, inclusive, from terminals 2 to terminals 3 in their respective banks 144. At position 4 the L3 brush makes contact with the master ground through conductor 211, left hand outer contact of relay 204, conductor 208, conductor 212, distributor brush 154, associated terminal 3, conductor 275, to the tens column of the multiplier bank 101. Since the digit 5 cross-line is connected with the tens column, the ground is extended through conductor 276, the winding of a multiplier relay 277 representing the digit 5, to battery. The operation of the relay 277 closes all of its leads to the proper junction points on the multiplying commutator 105 to ground. As the multiplier commutator rotates and makes contact $91 the units part of the results of 5x7, 2, 2, 9 and 3, respectively, ground from the armatures of the multiplier digit 5 relay 277 is connected to the denominational columns in the multiplicand key bank 100, through contact closures to the proper digit cross-lines, through the contacts of relay 217 to the corresponding brushes 149 to 153, inclusive, of the distributor switch 106. This switch is now on terminal 3 and the HT, TT, TH and T accumulator magnets 186 and associated holding relays 236 are operated at the proper times to accumulate 5, 0, 0, 5, and 5 on the brushes 165, 164, 163, 162 and 161, respectively, of the accumulator 107.

At position 15 the accumulator magnets 186 are released, the carry relay 215 operates, and any required tens carry is made as previously described. At the same time the distributor switch 106 is advanced to terminal 4 by the L2 brush of the control commutator 145 closing a circuit from battery to ground and operating the electromagnet 148. During the next half cycle, positions 15 to 28, the tens part of each of the products or" 5x7, 2, 2, 9 and 3 are registered as described above except that the distributor switch, being on terminal 4, now routes them to accumulator magnets M, TT, HT, TH and H (Fig. 2). At the end of this registry the tens carry function is again performed, the distributor switch is advanced to terminal 5 and the multiplicand 7 ,229.3 is multiplied by the hundreds digit 1 of the multiplier in a manner analogous to that described for multiplier digits 9 and 5. The distributor switch is then advanced to terminal 6 and the final tens carry is performed.

Upon the completion of this cycle, the product of 7,229.3 and $1.59 is standing in the accumulator 107 and the distributor switch 106 is advanced to terminal 7 by the L2 brush of the control commutator, closing the winding of the electromagnet 148 from battery to ground. As the L3 brush makes contact at position 4, the master ground is routed by distributor brush 154 through terminal 7 in its associated bank 144, conductor 280, the winding of the release relay 205 to battery and ground. The operation of the release relay opens its back contact and thereby removes battery from the pick-up relay 204, releasing it and restoring all parts of the system to normal. except the accumulator brushes which retain the product.

It is to be noted that no multiplier relay 277 is operated when multiplying by digits 1 or 9, but there is one provided for each of the multiplier digits 2, 3, 4, 5, 6, 7, and 8. These relays are used to prevent errors which in some instances might occur through the connecting circuit for one digit while multiplying by another if these relays or similar means were not provided; that is, the relays 27 7 are so arranged that two connected unused multiplier circuits cannot make electrical contact closures through the commutator simultaneously.

To restore the accumulator brushes to their normal position the clear-out switch 202 is thrown to the right, thereby opening .the circuit to ground from the accumulator brushes and closing another circuit from ground through conductor 281, the windings of relays 282 and 283 to battery. The operation of these relays connects ground on the Z brushes of the disks 261 to 267, inclusive, associated with the accumulator brushes 161 to 167, inclusive, whereas due to the insertion of the plug 'in the units (U) transfer Jack 192, ground is connected to the 5 brush of gr v.)

the disk 260 associated with the accumulator brush 160. The windings of the accumulator magnets 186 are connected from the Z to the F brushes of the disk to battery whereby the accumulator magnets are operated to cause rotation of the accumulator brushes and the disks. As each of the accumulator brushes 161 to 1671, inclusive, arrive at normal position, zero (0), the Z brush meets a break 258 in the dial; which opens the circuit releasing the accumulator magnet and stopping the accumulator brush on ll. The operation of the relay 283 connects ground on the 5 brush associated with the disk; 260 through conductor 225 (Fig. 2) contact 256 or the units (U) transfer jack 192, conductor 257, the 5 brush of the disk 260, through the disk 260 and the associated F brush to battery whereby the units (0) accumulator magnet 186 is operated to cause rotation of the accumulator brush 160 and the disk 260. As the accumulator brush 160 arrives at terminal 5, the 5 brush of the disk 2'50 meets the opening 258 (Fig. 8) in the disk 260 which opens the circuit, releasing the units (U) accumulator magnet and stopping the accumulator brush 160 on five.

The multiplying system is now in condition to perform another mathematical problem whereby the digit in the tens (T) denominational column of the result will be increased by one when the digit in the'units (U) column to be discarded is five or greater.

In the example hereinbefore described, the units (U) denominational register was caused to return to five instead of zero, but it will be understood that the tens ('l), hundreds (H), and

ten-hundreds (TH) denominational registers can also be returned to indicate five when that particular denominational column is to be discarded so that the digit in the preceding denominational column of a computation will be automatically increased by one when the digit discarded is five or greater.

What is claimed is:

l. in a computing system, means for performing a computation, means controlled thereby for registering the result of the computation, and means for automatically increasing the value of a digit by one in any one of a plurality of desired denominational columns of the registering means when the fractional part of said digit exceeds a predetermined number comprising selectively op erable contact making means for entering a digit in one of the registers when the other registers are cleared out.

2. In a computing system, means for performing a computation, an indicating means connected therewith, means for operating the computing means to efiect a computation and the operation of said indicating means accordingly, and means for increasing the value of a digit in any one of a plurality of selected denominational columns oi the result as shown by said indicating means when the fractional part of said digit exceeds a predetermined number comprising means for entering a digit in one of the columns when the other columns are cleared out.

3. In a computing system, a computing means, an indicating register connected therewith, means for operating the computing means to effeet a computation, and means for increasing the value of a digit in any one of a plurality of denominational columns of the register when the digit in the next lower denominational column of the register to be discarded is five or greater comprising a contact disk associated with each column of the register and an electric circuit controlled by the contact disk of the column of the register to be discarded for returning the column of the register to be discarded to the five indicating position.

4.. In a computing system, means for setting up a multiplicand and a multiplier, means controlled by the setting up means for performing a multiplication and indicating the product, and means operative simultaneously with the multiplying and indicating means on the return there- 01" to zero for selecting and increasing the value of a digit in the product of a succeeding multiplication by one when the digit in the next lower denom'national column selected is to be discarded and is five or greater comprising selectively ef' c tive electrical contact making means operated by said lower column.

5. in a computing system, an accumulator including a series indicating elements, means for returning the indicating elements to zero, and means operated. by the zero return means for controlling any desired one of a plurality of the elements to indicate the digit live.

6. in a computing system, an accumulator cluding a series of indicating elements, means for returning the indicating elements to zero, selective means for controlling a predetermined elern'ent to indicate the digit five simultaneously with the return of the other elements to zero, and means ior carrying tens to the next higher denomination when five or greater is added to the selected predetermined element.

7. In a computing system, an accumulator comprising av plurality of elements, means for returning the elements to zero, means for selectively operating the zero return means for returning an element to indicate the digit five, means for rotating the elements to register digits, controlling means adapted to be conditioned by a partial revolution oi said elements, and means controlled thereby for simultaneously making a plurality of tens carries to higher denominational columns.

3. In electrical computing system, an accumulator including a plurality of indicating elem nts arranged in denominational columns, means including an electrical contact making device arranged to be actuated by an element for establishing circuits to cause one of said denominational elements to indicate live at the start or" the registering of digits, means for rotating each element at a predetermined time including electro-magnetic means for holding the elements in rotation to indicate digits, and means for releasing said holding means at a predetermined time to stop rotation of the indicating elements.

9. In an electrical computing system, means for setting up a mathematical problem, a source of electrical energy, means controlled by the setting up means for establishing electrical circuits to obtain the result of the computation, means for registering the result of the computation, and means for preparing the registering means to automatically increase the value of a digit in the result by one when the digit in the next lower denominational column is to be discarded and is five or greater comprising an electrical circuit rendered effective by the registering means while returning to zero indicating position.

10. An electrical computing system, a computing means, a counting mechanism electrically controlled by the computing means for indicating the result of a computation, and. interchangeable means rendered eifective by the indicating means for increasing the value of the digit by one in a predetermined denominational column of the result when the digit in the next lower denominational column is five or greater and is to be discarded.

11. An electrical computing system, means for indicating the result of a computation, electrical means for effecting the actuation of the indicating means, a computing means for controlling the electrical means and effecting the actuation of the indicating means, means for setting up a mathematical problem to control the computing means, and electrically controlled means for controlling the electrical means for effecting the actuation of the indicatingmeans to increase the value of a digit by one in the result shown in the indicating means when the digit in the next lower denomination thereof is to be discarded and is live or greater.

12. An electrical computing system, means for setting up a mathematical problem, an accumulater having denominational columns, electrically operated means controlled by the setting up means for obtaining partial results and entering them in the proper denominational "columns of the accumulator to accumulate the final result therein, and electrically controlled means to control the accumulator for increasing the value of a digit in the final result by one when the lower denominational columns thereof are to be discarded and the next succeeding digit is live or greater.

l3. In an electrical computing system, means for setting up a multiplicand and amultiplier, electrical devices controlled by the setting up means for forming products, a driving means, a totalizer, mechanism actuated by the driving means under the control of the electrical devices for entering the products on the totalizer, and means for increasing the value of a digit by one in the result when the next succeeding digit is to be discarded and is five or greater, said last mentioned. means including control disks mounted on the totalizer, selectively operable control means associated with the control disks, and means interconnecting the control disks, the selectively operable control means and the product entering mechanisms.

14. An electrical computing system, a register including a plurality of rotatable contact elements, a plurality of register wheels operatively associated therewith, means for actuating the elements and register wheels, computing means for establishing circuits to control the register to indicate the result of a computation, and means including said actuating means and controlled by the contact elements for automatically returning any desired denominational register wheel to a five indication at the completion of a computation.

15. In a computing system, a computing means for forming a result, a plurality of elements for indicating a result, and interchangeable means for automatically returning a selected one of a plurality of the indicating elements to a five indication at the completion of a computation.

16. In a computing system, means for performing a computation, register means operative in a certain direction in accordance with the operation of said means for registering the result of said computation, and means effective after a computaton for operating said registering means in the same direction to clear it of said indication and to indicate therein automatically a number other than zero and which may be other than the result of the previous computation.

17. In a computing system, means for performing a computation, a plurality 01? indicating elements, means for rotating said elements in a certain direction in accordance with the operation of said computing means, means operated following a computation for controlling the further rotation of said elements in the same direction and their return to zero, and means for causing at least one of said elements to continue its rotation to indicate a number other than zero and which may be other than the result of said computation.

18. In a computing system, means for performing a computation, a plurality of indlcatng elements, means for rotating said elements in a certain direction in accordance with the operation of said computing means, means operated following a computation for controlling the further rotation of said elements in the same direction and their return to zero, and means selectively operable independently of said computing means for causing at least one of said elements either to indicate zero or to continue its rotation and indicate a number other than zero.

19. In a computing system, means for performing a computation, a plurality of register elements, means for causing the operation of said elements to register a number in accordance with the operation of said means, a reset switch for controlling the further operation of said elements in the same direction to return them to zero position, and means arranged to cause certain of said elements to pass through zero and register a higher digit.

20. In a computing system, means for performing a computation, a plurality of register elements, means individual to each of said elements and responsive in accordance with the operation of said computing means for operating said elements to register the result of a computation, means for causing the simultaneous operation of said second nrentioned means to return said elements to zero position, and means for operating at least one of said elements through its zero position to indicate anynumber other than zero.

21. In a computing system, means for performing a computation, a plurality of register elements, electromagnetic means individual to each of said elements and operated in accordance with the operation of said computing means for controlling their operation to register the result of the computation, means for simultaneously completing electrical circuits for said electromagnets to effect the return of said elements to zero position, and means for continuing the electrical circuit of the electromagnet of at least one of said elements for causing said element to indicate a number other than zero.

22. In a computing system, means for performing a computation, a plurality of register elements, means for causing the operation of said elements to register a number in accordance with the operation of said computing means, means for causing said elements to be returned to zero position by adding to decumulate, means for insuring that said elements assume a zero position, and means for rendering said last mentioned means of at least one of said elements inefiective to cause its operation to indicate a number other than zero.

23. The combination of numeral wheels, differential actuating means therefor, clearing means for said numeral wheels, carrying means for carrying from one denomination to another of said numeral wheels, and means associated with said clearing means for setting one of said numeral wheels to a position substantially half-way between cleared position and carrying position.

24. The combination of 'a plurality of numeral wheels, difierential actuating means therefor, clearing means for said numeral wheels, tens-carrying means for said numeral wheels, and means associated with said clearing means for setting one of said numeral wheels to its 5 position upon clearing other of said numeral wheels.

25. In a calculating machine, the combination of a plurality of numeral wheels of successive denominational orders, tens-carry means associated therewith, and clearing means optionally operable to return all of said wheels to similar relationship with said tens-carry means, or to return one or said wheels to such position as to effect an early carry upon subsequent actuation of such wheel.

26. The combination of a numeral wheel a zero setting stop control element and a secondary stop control element, and a member movable from one position to another for rendering the numeral wheel effective with relation to the said zero setting stop control element or the secondary stop control element.

27. The combination of a numeral wheel means for controlling the stopping of the wheel at zero and a secondary means for stopping it at a position other than zero, and a movable means optionally operable for rendering the numeral wheel effective with relation to the zero stopping means or the secondary stopping means.

28. In a computing system, computing means, an indicating register connected therewith including a plurality of register wheels in denominational columns, means for operating the computing means to effect a computation, and means for increasing the value of a digit registered on the register wheel in any one of the plurality of denominational columns of the register when the digit in the next lower denominational column selected is to be discarded and is five or greater comprising a contact disk mounted to rotate with each register wheel, and an electrical circuit selectively controlled by the contact disks for causing the said lower register wheel to be returned to the fiveposition.

29. In a computing system, means for performing a computation, a plurality of indicating elements, means for rotating said elements in a certain direction in accordance with the operation of said computing means, means operated following a computation for controlling the further rotation of said elements in the same direction and their return to zero, and means for causing at least one of said elements to continue its rotation to indicate a number other than zero when the digit stored therein at the completion of the computation is greater than a predetermined amount, and to stop its rotation at a point where it indicates said number other than zero before passing through zero indicating position when the digit stored therein at the completion of the computation is less than said predetermined amount.

30. In a computing system, means for performing a computation, a plurality of register elements, means individual to each of said elements and responsive in accordance with the operation of said computing means for operating said elements to register the result of a computation, means for causing the simultaneous operation of said second mentioned means to return said elements to zero position, and means for operating at least one of said elements through its zero position to indicate a number other than zero when the digit stored therein at the completion of the computation is a predetermined amount or greater than said predetermined amount and to stop its rotation at a point where it indicates said number other than zero before passing through zero position when the digit stored therein at the completion of the computation is less than said predetermined amount.

31. In a computing system, means for performing a computation, a plurality of registerelements, electro-magnetic means individual to each of said elements and operated in accordance with the operation of said computing means for controlling their operation to register the result of the computation, means for simultaneously completing electrical circuits for said electromagnets to effect the return of said elements to zero position, means for maintaining the elec-= trical circuits to the electromagnet of at least one of said elements until said element or elements indicate 5, and means for automatically breaking said circuit or circuits when the element or elements reach the 5 indicating position.

32. In a computing system, means for perform:- ing a computation, a plurality of register ele ments, electromagnetic means individual to each of said elements and operated in accordance with the operation of said computing means for controlling their operation to register the result of the computation, means for simultaneously completing electrical circuits for said electromagnets to effect the return of said elements to zero position, and means for maintaining the electrical circuit to the electromagnet of at least one of said elements for causing the one of said elements to return to a position where it indicates a number other than zero.

33. In a computing system, a plurality of register elements, computing means for operatively controlling the elements to enter digits thereon, and means for establishing electrical circuits to return some of the elements to zero position and to cause other of the elements to indicate a number other than zero.

34. In a computing system, a plurality of register elements of successive denominational orders, means for returning the register elements to zero, tens-carrying means for the elements, and means operatively associated with the zero return means and tens-carrying means for controlling any desired one of a plurality of the elements to indicate a number other than zero during the return of the other elements to zero position.

35. In a computing system, a plurality of register elements, means for actuating the elements, means for establishing and disrupting electrical circuits to control the actuating means in returning the elements to zero, and means associated therewith for causing one of the elements to inclicate a number other than zero.

36. In a computing system, a computing means, a plurality of register elements, electromagnetic means associated with the computing means for controlling the operation of the register elements, means for establishing electrical circuits for said electromagnets to effect the return of the elements to zero position, and means for controlling the electrical circuit of a selected element for selectively causing that element to indicate zero or a number other than zero.

3'7. In a computing system, registering elements, means for actuating said registering elements to cause them to indicate a result, means for clearing said registering elements, means for storing 5 in one of said elements when the other elements are returned to zero, and means for rendering said last mentioned means effective or ineffective at the will of the operator.

38. In a computing system, registering elements, clearing means for said registering elements, means for stopping said registering elements in a zero indicating position upon the operation of said clearing means, means for stopping one of said registering elements in a position other than zero upon the operation of the clearing means, and means for controlling the operation of said last mentioned means.

39. In a computing system, registering elements adapted to be restored to zero, means for storing 5 in one of said elements when the other elements are returned to zero, and means for rendering said last mentioned means efiective or ineffective at the will or the operator.

40. In a computing system, registering elements adapted to be restored to zero, means for stopping one of said registering elements in a position other than zero, and means for controlling the operation of said means.

41. In a computing system, an accumulator including a plurality of registering elements for registering the result of a computation, means for actuating said elements to register a result therein or to clear a result therefrom, means individual to each of said elements for rendering said actuating means inefiective with respect thereto when the element reaches the zero indicating position in clearing a result from the elements, and selectively controllable means individual to each of a plurality of said elements for rendering said last mentioned means ineffective and for rendering the actuating means ineffective when the elements reach a 5 position in clearing a result from the elements.

42. In a computing system, an accumulator including a plurality of registering elements, means for actuating said elements including computing mechanism and clearing mechanism, means normally operable to stop said elements in a zero indicating position upon operation of the clearing means, means individual to each of a plurality of the elements for stopping any one of said last mentioned plurality of elements in a position other than zero, and control means for selecting the element to be returned to a position other than zero.

43. In a computing system, a plurality of registering elements, means for controlling said registering elements including a computing mechanism and a clearing mechanism, means for stopping the elements at a zero indicating position upon operation of the clearing mechanism, means for stopping any one of a plurality of said elements at a position other than zero upon operation of the clearing mechanism, and control means for selecting one of said last mentioned plurality of elements for return to a position other than zero upon the operation of the clearing means.

44. In a computing system, registering elements for accumulating values, means for clearing said registering elements, and means for storing a predetermined number other than zero in one of said elements when the other elements are returned to zero. g,

45. In a computing systems, registering elements for indicating a result, means for clearing the registering elements, and selective means for storing five in one of the registering elements when the other registering elements are returned to zero.

46. In a computing system, a series of indicating elements, means for returning the indicating elements to zero, and means operatively associated with the zero return means for controlling any desired one of the elements to indicate a predetermined digit other than zero.

47. In a computing system, a computing means, a plurality of elements arranged in denominational order for accumulating a result, means for selecting denominational orders to be discarded, and means for automatically increasing the value of a digit in a predetermined denominational order element when an amount of predetermined value is entered in the selected denominational elements.

48. In a computing system, a computing means, an accumulator controlled by the computing means and including a plurality of denominational elements, interchangeable means for selecting one of a plurality of the denominational elements, and means for causing the selected element to operate a predetermined amount so as to increase the value of the digit in the next higher denominational element when the digit in the lower denominational element of the result is to be discarded and is of a predetermined value.

49. In a computing system, a plurality of denominational order elements for accumulating a result of a computation, and means including an electrical contact-making device for automatically adding a digit to a lower denominational order to be discarded for increasing the value of the preceding digit when a digit of predetermined value is added to the said lower denominational order during a computing operation.

HAROLD GLENN JOHNSTONE. 

